Stem cell-based therapy for systemic sclerosis.

Autoimmune diseases, including SSc, are prevalent, affecting autologous connective tissues and caused by the breakdown of self-tolerance mechanisms of the immune system. During the last 2 decades, stem cell therapy has been increasingly considered as a therapeutic option in various diseases, including Parkinson's disease, Alzheimer's disease, stroke, spinal cord injury, multiple sclerosis, inflammatory bowel disease, liver disease, diabetes, heart disease, bone disease, renal disease, respiratory disease and haematological abnormalities such as anaemia. This is due to the unique properties of stem cells that both divide and differentiate to the specialized cells in the damaged tissue. Moreover, they impose immunomodulatory properties affecting the diseases caused by immunological abnormalities such as SSc. In the present review, the efficacy of stem cell therapy with two main types of stem cells, including mesenchymal stem cells and hematopoietic stem cells, will be reviewed. Moreover, other related issues, including safety, changes in immunological parameters, suitable choice of stem cell origin, conditioning regimen and complications of stem cell treatment will be discussed.